Dynamics and control design via LQR and SDRE methods for a maglev system

Abstract

Several experimental maglev systems all around the world, mainly in Germany and Japan have demonstrated that this mode of transportation can profitably compete with air travel. However, a system such as the German maglev train (called Transrapid) is inherently unstable. This instability is because the electromagnetic suspension (EMS) uses attractive force to levitate the train. So, the electromagnets of the vehicle must be actively controlled to make safe operation. Herewith, from a simplified model for the German Transrapid experimental system, we propose two control designs and, then we compare them. The linear quadratic regulator (LQR) is used to design the linear controller and the state-dependent Riccati equation (SDRE) is used to design the nonlinear controller. The simulation shows that the SDRE controller allows the maglev train to operate with much larger disturbances in the air gap than the LQR controller does.